v5 wrx factory boost

[ajb86n]

Hey all

Anybody know what a 99 wrx standard boost level should be??

[boon]

Pretty sure it's 1 Bar - 14psi?

[ajb86n]

is the wot

I havent pushed it hard in 5th but im only getting 0.5-0.7 boost leak somewhere ya reakon??

[boon]

Nah it would run like a sack of **** if you had a boost leak that big. More likely an issue with boost control, in this order:

-Pill missing from compressor housing boost line

-ECU in limp mode, limits it to 0.5 Bar

-Some sort of problem with the boost control, likely the solenoid, OR someone has monkeyed with it.

[Marky]

Is the car completely, totally untouched?

Also if it's detecting a decent amount of pinging (say, running 91/95 gas and/or a hot day) it'll pull boost too

There's a few reasons it will run less boost, either deliberate action by the ECU (due to knock or fault detected), due to faults (boost leak, solenoid stuck closed) or due to people fiddling (pick your poison, missing restrictor, fcked up vacuum lines, whatever)

With a 16ish year old WRX it's likely the second two

[Marky]

Great minds aye

[ajb86n]

wicked few ideas there to smash into tomorrow

Na marky car has been fiddled with alot from the looks of things got it last nite and the guy didnt know to much bout it.

Any one got any engine bay pics i can use as a guide and also highlighting any restrictor pills would be a big help too

Cheers for ya responses

[Rosssub]

The restrictor pill should be where the white paint dot is in this pic:

Here's a pic showing the complete OEM boost control set up:

It might of had an EBC fitted that's been removed, then replaced with a straight hose from turbo-WG giving WGSP.

Edited October 8, 2015 by Rosssub

[pedro]

Did you change the oil after you bought it and before you thrashed it ?

If not it may pay to do some basic maintainence before you find the extra boooooost..

[ajb86n]

Cheers rossub ur onto it alright appreciate it mate

pedro na not yet was gona be my weekend mission

no doubt I'll run into more problems so watch this space lads lol

cheers for ya help

[Guest]

Sure my v5 non sti was 12psi stock. Td04.

[max.]

 evowrx said:

Sure my v5 non sti was 12psi stock. Td04.

Seconded, that is until i installed an aftermarket downpipe. Then up to 14psi.

[ajb86n]

12 u say good as I'll be working on it today so will keep everyone updated

[ajb86n]

so ive added a restrictor pill into hose 1 off turbo to wastegate but now im getting 12-14 psi or 1.0-1.2 on my guage but holds for a second then boost drops to around 4 psi and just repeats process any ideas??

[boon]

Got any carby cleaner or AFM cleaner? Chuck a good dose of it in the boost control solenoid, from both sides, ideally while triggering it.

[ajb86n]

Triggering it??

yea boon ive got both carby cleaner would be the good wouldnt it

also is there a cetain spot the pill needs to be ive got it just abit closer to the wastegate side of the hose

[boon]

Triggering = turning it on and off so you can get some carby cleaner up in the actual mechanism of it.

[ajb86n]

yup got it ill give that a go soon cheers boon

[Rosssub]

Use test mode to clean out the boost solenoid (carby cleaner). Green plugs under the dash (ignition on/engine off), makes the solenoid trigger open-closed.

1.0bar is 14.5psi - 1.2bar is 17.4psi. The pill should be on the compressor side of the T-piece as in the earlier pic's. Did you poke some wire through the hose to check there wasn't already one in there? Could also be the wrong sized pill. According to the below link it should be a 0.9mm pill. So a TT 0.8mm pill will be too small and make boost run higher:

http://www.perth-wrx.com/vb/mechanicals/48287-restrictor-pill-what-why-you-need.html

If cleaning out the boost solenoid doesn't help, try blocking the BOV off to see if it helps. Then try a boost leak test.

[ajb86n]

it will be the pill size then rossub as i pulled it out of a tt hose. but would that cause it to hit full boost then drop to 4 psi then shoot back to full boost and drop down again

ive tryed every gear and happens in all.bit stumped.

side note does the standard blowoff valve make much noise on wrxs as i cant seem to hear a thing when changing gears this is my first time owing a wrx and dont have to many people that have one to compare

[Rosssub]

Probably only if it's boost cutting, which it could be. I would run a straight hose from compressor housing to WG until you can get the right sized pill. My OEM BOV doesn't make a sound.

You can check the diaphragm inside the BOV by connecting a vac hose to the BOV actuator nipple, then sucking on the hose. Then block the end of the hose with your tongue and see if it hold vacuum. If it wont hold then the diaphragm is split.

Or block the BOV recirc hose off completely to see if it helps. Again showing the BOV could be opening at full boost.

Or try a boost leak test. Block the intake off at the AFM:

Then pump 15psi into the manifold with an air compressor. Any leaks will be obvious:

[ajb86n]

sweet will give that a go.

do you mean remove pill and leave it the way it was

hose off turbo to the t peice to wastegate and t hose running to the boost solinoid correct??

[Rosssub]

Yeah that will do it. Should give a stable 7psi. If you don't have easy access to a 0.9mm pill you can use a mig welding tip. I've used a shaft from a nitro RC carby and also a piece of plastic 5mm long with a 1.0mm hole drilled through it.

[Marky]

Can also be if the afm is a bit shifty it'll think it's reading way high, especially if it has other breathing mods (i.e for example you can trigger boost/fuel cut with 15psi stock, or at 12psi with it opened up through exh and intake mods, or a cold night etc etc)

I would be suggesting give the car a proper clean bill of health before worrying about getting the boost wound up

BOV will be near silent, just a "chuff" you can hear back through the intake if you listen hard enough

[ajb86n]

solid cheers lads for your input gota shoot off to work now so till tomorrow

Marky on the afm note i noticed i have the same afm as my old bh legacy had is that spose to be correct